Method and means for controlling internal-combustion engines



May 22, 1923. 1,456,337

C. G. PULLN METHOD AND NEANs EOE coNTEoLLING INTERNAL coMEusTIoN ENGINES Filed Jury 2o. 1920 A Hor/Wy.

Fatente'd May 22, i923.

UNrrsn risers? Application filed July 20, 1920.A Serial No. 397,563."

To all whom t may concern:

Be it known that I, CYRIL GEORGE PULLIN, a subject of the King of Great Britain, residing at Isleworth, l iddlesex, England, have invented an Improved Method and Means for Controlling Internal-Combustion Engines, of which the following is a specification.

This invention relates to an improved method of controlling internal combustion engines, and has for its object to provide means whereby only predetermined volumes of the combustible mixture are subjected to full compression.

Generally speaking, the admission of a Combustible mixture to the cylinder is controlled by levers regulating the flow through the fuel orifice from the carburetter or from the mixing chamber of the carburetter.

According to this invention, the control is effected by releasing or exhausting aportion of the combustible mixture admitted to the combustion chamber during the compression stroke so that only a portion of total charge is subjected to full `compression, thereby regulating the output of the engine.

The invention consists in a method of controlling an internal combustion engine in which a portion of the charge admitted through the combustion space is returned to the source of supply, before ignition takes place in the cylinder, the amount returned determining the compression in the combustion space, and in themeans of effecting the removal of a predetermined portion of the charge to the combustion space.

Broadly speaking, the means consists of a spring controlled valve with a wire drawing passage and means for adjusting the tension of the spring whereby the said wire drawing tends to raise internal pressure, so as to close the said valve against the action of the said spring when the predetermined pressure regulable by the spring, is

reached.

In order that my invention may be clearly understood, I will now describe the same with reference to the accompanying drawings, in which, Fig. l shows in central vertical section, an internal combustion engine, fitted with a control means, constructed according to this invention, and Fig. 2 is an elevation of the control means partly in section and to an enlarged scale.

The engine illustrated 'from the' drawings, 1s of a two-cycle type and the cylinder CYRIL GEORGIE PULLIN, OF ISLEWORTH, ]i}1\TG-LA1\TID.

and c rank case, as shown, are cast in one, and in the cylinder wall, a transmission passage is formed, runningalong its length and connecting the crank chamberbyv ports running through the inner end of the cylinder, the crank case having formed in one side an induction passage, being al' continuationV of the. said transmission passage running lengthways of the cylinder, and so formed as to be connected to they supply of mixture from the carburetter.

The crank case is preferably formed with a detachable side plate and the cylinder with a detachable head so that the piston and its connecting rod can be inserted through the open end of the cylinder and Yplaced in position on the crank shaft with ease.y

For a clear understanding of ythe invention, the engine shown in Fig. 1 will first be described, and thenits operation, and afterwards the effect of the control valve on such operation will be referred to.

Referring rst to Fig. l, theengine piston l :works in the cylinder 2, cast in one with a closed crank case 3 of an internal combustion engine, the piston having "a perforated skirt 4 and a deector head 5 with transverse cruciform webs 6, internally arranged, the piston being driven from a crank disc 7 to which it is connected bya gudgeon pin 8 and a connecting rod 9L The gudgeon pin 8 is of a hdllow type and particularly connected to its connecting rod,so as to provide a clearance between the connecting rod and the bearings of the gudgeon-pin By this means the piston and its connecting rod can be inserted in the cylinder before i the detachable head 10 is secured in position, and, due to the clearance justreferred to, the connecting rod can be slightly tilted until it is in position to pass on to the crank pin of the crank disc 7. The cylinder is v formed as before stated, with a transmission passage l1 provided in the wall of the cylinder and which is connected to both ends of the combustion space at the lower pressure end by an inlet port 12 and at the" high pressure end by an outletl port l13. The crank case 3 is formed within its wall with an induction passage 11il communicating with the transmission passage 1l and leading from an induction valve l5 to the crank chamber via .a port lfThe exhaust openings 17 are formed substantially opposite the inlet ports 12 in the cylinder 2. T

The numeral 35 indicates the silencer for the engine. i

The cycle of operations, when the engine is running on fullcharge, is as ollowsz'- The piston 1 makes an outstroke, and due to the reduction of pressure and to an ultimate negative pressure in the crank case 3, mixture is sucked in through the induction passage 14 yormedin the wall of the crank case 3, through the port 16 at the crank case end of the cylinder, and then through the skirt, l of thepiston, or behind the piston to the crank case. The piston then makes an instroke, compressing the charge in the crank case and 4driving it out through or behind the piston, through the port16 to the transmission passage 11 formed longitudinally of the cylinder, and through the cylinder inlet ports 12 on the firing side o f the piston, to the combustion space. The piston then again advances on an outstroke, compressingthe mixture in the combustion spaceV of the cylinder, closing the inlet ports 12 to the cylinder and the exhaust ports 17 from the cylinder, while at the same time inducing a Jfresh charge to the crank case. At the commencement of the next instroke, the ignition 'of the gases is effected and the working stroke commences, again compress ing the charge lin the crank case, then driving it out through the said port 16 1n the crank case end of the cylinder wall, upthrough the7 transmission passage, and through the inlet ports 12 to the combustion space, the new charge being so directed 1n itsentry by the delector head 5 of the piston tothe combustion space of the cylinder, that it drives out the bur-nt gases through the exhaust ports 17 which have been s1- multaneously uncovered with the inlet ports 12 as the piston completed its instroke. The

`scavenging have been eiieeted by the new charge, a new cycle of operations commences.

Now when the speed of the engine is required to be modified, a portion of the charge admitted to, the combustion space is permitted to escape through the outlet 13 and back down the transmission passage 11 to the source of supply; in this case the closed crank chamber 3.

This control valve, is so constructed as to automatically close, when a, predetermined pressure in the combustion space is obtained, that is, when the predetermined portion of the charge to be removed has passed through the outlet 13.

rlhe preferred construction of this control valve will be afterwards described, with particular reference to Fig. 2.

The induction' valve 15 is of the type influenced by the negative pressures in the v crank chamber obtained on the successive upstrokes of the piston and in the construm tion shown, the valve is of that type, which, when operated tov admit fuel to the mixing chamber 37 for supplyl to the crank case,

Valso permits a flow of lubricant through a suitable conductor, such as 38, to the distributing' port 39, substantially midway of the engine cylinder, so that the piston is always automatically supplied with oil, while the engine is working.

l It will be obvious with such a constructLon, the valve 15 will lift according to the negative pressures in the crank case, and the negative pressures will vary according `to the amount oi gases removed from the. combustion spacei and return to the crank case.

The reference numeral 2O designates a silencer for the exhaust gases.

The control valve 18 is provided withV an extended spinde 19 and the seating for the valve is formed by a guide member 20 provided with circumferential openings 21 communicating with the interior of= the guide member. The head of the valve v1,8 is further provided with depending flanges 22 riding within the guide member and having ports 23 formed therein, and adjacent the head ot the said valve.

It will be seen by this construction, that the member 20 guides the valve 18 by providing a path of movement for thek spindle 19 and for the depending iiange'22. The guide member 20 also forms on its inner extremity 24 the seating for the valve, the guide member 20 being retained in position by a casing 25, hereinafter referred to as the valve casing, which is retained in position in the wall of the cylinder by an externally gland member 26 engaging internal threads formed within the eXtension of the outer wall adjacent the outlet 13. By screwing down the gland. 26, the casing 25 presses the guide 20 against the inner face 27 of the transmission passage 11. The valve spindle 19 has a threaded extremity 28, on which is Xed a nut member 29 and the compression spring 30 is disposed between the end of the casing 25 and the said nut member 29. A sleeve member 31 which is slidably disposed on the spindle 19, limits the movement of the valve spindle impressed by the spring 3()` on the nut 29, by reason of its abutting against the said nut, and by the provision of a projection 32 preferably in the form of a, handle projecting from the said sleeve member through a slot 33 formed in the wall of the casing, the pitch of the slot beingy suiiiciently small to prevent the spring member eii'egctf ing a sliding movement of the projections 32 within the said slot.

It will be noted that the spring 3()-y al ways tends to, lift the valve` butr it is limitedin its eiect by the engagement of the sleeve member 31, which is slidable Within the valve casing, with the nut member 29 on the valve spindle.

In the initial position, that is, when the full charge in the engine cylinder is to be subjected to compression and ignition. the sleeve 3l is in its outermost position relative to the cylinder and by engagement with the nut 29 on the valve spindle as aforesaid, retains the valve on its seating formed in the wall of the cylinder.

l/Vhen the predetermined portion of the mixture is desired to be liberated from the compression space the sleeve member 3l is given a longitudinal displacement within the valve casing by operation of the control member 32. In this position the valve 18 is maintained oft its seating by the pressure of the spring 30, and the opening space between the valve and its seating is regulated by the amount of longitudinal dis' placement of the sleeve member 3l which as aforesaid, directly regulates the effective effort of the spring. ln this position of the valve from its seating, a portion of the mixture commences to flow from the combustion chamber as the engine piston commences its compression stroke, the expelled gases flowing out between the valve 1S and its seating, through the ports 23, in the depending flanges 22, then outwards through the internal space, within the guide 20 and out through the circumferential openings 2l to` the transmission passage ll. The flow of the gases between the valve and its seating obtain an accelerated velocity as the piston advances until the desired wire-drawing effect is produced, for as the mixture is unable now to quickly leave the cylinder, the pressure therein immediately rises and overcomes the effective effort ofl the spring member, whereon the valve closes on its seating and thereafter' the usual cycle of the engine follows.

t will be seen then that according to the position of the sleeve within the valve casing the opening between the valve and its seating will vary, and accordingly the wire-drawing effect will take place at differentpositions of the piston in its compression stroke, and that as the desired position of the stroke is obtained the compression in the cylinder overcomes the effect of the spring at that position and compression of the desired proportion of the total charge in the cylinders is effected and subsequently ignited in the usual way.

Graduations 34C may be formed along the slot or in any suitable way, either to show the tensional effort of the spring in each position, or to show the position of the piston vin the working cylinder when the choking or wire-drawing effect obtains the closing of the combustion space.v

I claim l. Means for controlling an internal combustion engine, comprising a spring-controlled valve member having a wire-drawing passage, and means for adjusting the tension of the spring, whereby the said wiredrawing tends to raise the internal pressure so as to close the said valve against the action 0f the said spring when a predetermined pressure, regulable by the spring, is reached.

2. In an internal combustion engine, means for regulating the compression in the combustion space, by controlling the exit therefrom of' a portion of the charge, comprising a valve, a seating therefor at the high pressure end of said combustion space, wiredrawing passages between said valve and seating, a spring tending to keep said valve from said seating, and means for adjusting the lift of the valve effected by said spring, whereby the said wire-drawing tends to raise the internal pressure so as to close the said valve against the action of the said spring when a predetermined pressure, regulable by the spring, is reached.

il. Means for regulating the compression in the combustion space in an internal combustion; engine, having in combination a working cylinder having an exit at the high pressure end of the combustion space, a valve seating' in said exit, a valve, a valve spindle, said valve having wire-drawing openings in the head thereof, an enlargement at that extremity of the spindle away from the head, a guide for said, spindle, a casing for said `valve spindle, means securing said casing to said engine cylinder, a spring within said casing pressing against said enlargement on the valve spindle and tending to lift the valve from its seating, means engaging the other side of said enlargement for limiting the lifting movement of said valve, and means-operable from outside said casing for adjusting the position ot said valve lift limiting means.

1l. sans for regulating the compression in the combustion space of an internal combustion yengine having inv combinatiom, a working cylinder having a longitudinal transmission passage in the wall thereof and an exit from the combustion space at the high pressure end thereof, said transmission passage communicating with the said exit, a valve seating in said exit, a valve, a valve spindle, said valve having wire-drawing openings in the head thereof, an enlargement at that extremity of the spindle away from the head, a guide for ysaid spindle, a casing for said valve spindle, means securing said casing to said engine cylinder, a spring within said casing pressing against said enlargement on the valve spindle and tending to lift the valve from its seating, means engaging the other side of said enlargement for limiting the lifting movement of said valve, and means operable from outside said casing tor adjusting the position ot said valve litt limiting means.

5. Means for regulating the compression in the combustion space in an internal combustion engine,.having in combination a working cylinder having an exit at the high pressure end of the combustion space, a valve. seating in said exit, a valve, a valve spindle, said valve having wire-drawing openings in the head thereof, an enlargement removably attached at that extremity ot' the spindle away from the head, a guide tor said spindle, a casing for said valve spindle having a cam slot in the wall thereof, means securing said casing to said engine cylinder, a spring within said casing pressing against said enlargement on the valve spindle and tending to liit the valve 'from its seating, a hollow piston member slidable within said casing and having a central aperture tor the projection therethrough of the valve spindle and normall v abutting against said enlargement, a projection fixed to said hollow piston member and protruding through said cam slot in casing, and means 'for moving` said projection in cam slot whereby the litt ot said valve may be regulated.

6. Means tor regulating the compression in the combustion space ot' an internal combustion engine having in combination, a working cylinder having a longitudinal transmission passage in the wall thereof and an exit from the combustion space at the high pressure end thereof, said. transmission passage communicating with the said exit, a valve seating in said exit, a valve, a valve spindle, said valve having wire-drawing openings in the head thereoit, an enlargement removably attached at that extremity of the spindle away from the head, a guide for said spindle, a casing for said valve spindle having a cam slot in the wall thereof, means securing said casing to said engine cylinder, a spring within said casing pressing against said enlargement on the valve spindle and tending to litt the valve from its seating, a hollow pistou member slidable within said casing and having a central aperture for the projection therethrough of the valve spindle and normally abutting against Maase? said enlargement, a projection fixed to said hollow piston member and protruding through said cam slot in casing, and means for moving said projection in said cam slot, whereby the lift ot' said valve may be regulated.

7. In a two-stroke internal combustion engine, a mixture supply valve operable by the negative pressures in said crank chamber,l an induction passage leading from said valve to said crank chamber, means tor compressing the admitted volume by a stroke of the piston, a transmission passage for the compressed gases communicating with said induction passage, and connecting the crank chamber with both ends of the combustion space, means for automatically effecting a wire drawn ejection ot a portion of the gases 'from the combustion chamber to the trans- .mission passage, .vhereby the removed gases may be returned to a source of supply of gas on a subsequent cycle, supply means for ett'ecting the removal of a portion of the gases trom the engine cylinder, comprising in combination with the said cylinder, a valve disposed to control the communication between the higher pressure end of the combustion space and the said transmission passage, a valve seating in said communication, an extended spindle for said valve, Wire drawinol openings inthe head of said valve, an enlargement removably attached at that extremity ot the spindle of the spindle away from Ythe head, a guide for said spindle, a casing for said valve spindle having a cam slot in the wall thereof, means securing said casing to said engine cylinder, a spring Within said casing pressing against said enlargement on the valve spindle and tending to litt the valve from its seating, a hollow piston member slidable Within said casing and having a central aperture for the projection therethrough of the valve spindle and normally abutting against said enlargement, a. projection fixed to said hollowr piston member and protruding through said cam slot in casing, and means for moving said projection in cam slot whereby the lift of said falve may be regulated. y

In testimony whereof I aiix my signature.

CYRIL GEORGE PULLIN. 

